Java Mouse Deer, Tragulus javanicus

The Java mouse deer (Tragulus javanicus) is an even-toed ungulate that can be found in forested areas of Java and possibly Bali. Its native range includes areas in Indonesia and Malaysia. It prefers a habitat at higher elevations, although it does appear at lower elevations between 1,312 and 2,296 feet. It is thought that other chevrotains may occur on the edges of this mouse deer’s habitat, making it a logical assumption that it appears in thick undergrowth like other mouse deer.

The taxonomic status of the Java mouse deer is debatable, although it is currently classified as a mouse deer. Its scientific name was given by Grubb in 2005, although some experts suggest that it is not accurate. Because there is no physical data to study the species with that can be verified, it has been placed in the genus Tragulus with other mouse deer, or chevrotains. Its name was commonly used to represent large chevrotains, but it was found that these most likely do not occur on Java, and therefore, cannot be included with the Java mouse deer. It was suggested by Meijaard and Groves in 2004 that this smaller chevrotain is unique to the island of Java, making it a distinct species from all other chevrotains, but this has not affected its current classification.

Future review on the classification of this species is needed, because there are many species of chevrotain, or mouse deer, and it is not known how many exist alongside the Java mouse deer. There have been reports of two smaller subspecies of the Java mouse deer, which are related in appearance. However, this is not enough information to classify any subspecies under the Java species. There have also been findings of larger chevrotains on the island, making it even more difficult to properly classify the Java mouse deer.

There have been no field studies pertaining to the Java mouse deer specifically, but it is thought that populations are small due to lack of sightings when compared to other species. On the Dieng Plateau in Java, individuals were sighted in only five of teen study sites in 2008, leading experts to believe that the Java mouse deer is very shy in demeanor. One expert previously noted that this species was relatively abundant, so it is thought that the lack of sightings could also be caused by a decline in population numbers. Although a decline in population numbers is not the only possible cause of this, it is becoming rare to find in some markets located in Java.

Natural habitats in Java have become highly fragmented due to human populations growing. When the Dutch settled in Java, many protected areas were created, but these went into decline after Java gained independence until the 1970’s. Beginning in 1982, after Indonesia hosted the World Parks Conference, many more protected areas were designated, and conservation efforts increased due to funding by donors including the World Bank. Other protected areas like game and nature reserves that did not receive much funding remain in poor condition. Between the 1980’s and 1990’s, gun regulation caused an increase in snare and trap hunting, which may have affected the populations of chevrotain negatively. Habitat loss is not a major threat to this species, although some loss did occur due to illegal logging and agriculture. In 1997, after a large socio-political change affected the citizens view of police and law, hunting and illegal practices increased in protected areas.

The Java mouse deer is often found in markets in areas like Jakarta, Malang, Yogyakarta, and Surabaya. It is difficult to overlook these in markets, because they are typically found in small cages. The number of individuals found in most markets is relatively high, conflicting with the findings that they are rare in the wild. This species has been trapped and hunted for many years to be sold as pets and game meat. In recent years, the Java deer mouse has not been spotted as often as in the past, leading some to believe that the species is becoming harder to trap, and therefore, may be in decline. Hunting is thought to be a possibly major threat to the species. Because the Java mouse deer is still considered abundant in markets, it is thought that large populations must still exist in Java, or that the individuals found are imports from other areas of Indonesia.

The Java mouse deer has been protected by law since 1931, but hunting does occur. Conservation efforts must begin with a clearing up of any taxonomic confusion associated with this species, including information about the origin of each studied specimen. It is thought that efforts to understand this species must include searching through secondary forests and forest edges, where many species are not sought. This mouse deer appears on the IUCN Red List with a conservation status of “Data Deficient” and more information is needed about its habits, range, and population before any changes to its status can occur.
Image Caption: Tragulus Javanicus (Lesser Malay Mouse-deer) in the Jerusalem Zoo. Credit: Levg/Wikipedia (CC BY-SA 3.0)